You are wrong and I think it is important that you understand your error. Your mistake is that pulling the water out of a well that I own is not "the same as buying a bottle of water from a supplier".
I have pulled the water out of a well that I own, at a cost of $1 per bottle. The cost of production is constant, over the time period that the ferry is both available and unavailable. Therefore should the price that I am able to sell my water at rise due to constrained supply, I will make more profit. My profit margin will increase.
This is called "supply and demand", you will find it explained on Wikipedia, and it is a basic concept underlying markets of all kinds.
What I meant by "there is only one type of profit" is that profit in all your definitions can also be stated as selling price minus cost price. In the context of this discussion the distinction is meaningless, because regardless of how you obtained that margin, whether by speculation or not, it does not neccessarily tend to zero in open markets!
I have pulled the water out of a well that I own, at a cost of $1 per bottle. The cost of production is constant, over the time period that the ferry is both available and unavailable. Therefore should the price that I am able to sell my water at rise due to constrained supply, I will make more profit. My profit margin will increase.
This is called "supply and demand", you will find it explained on Wikipedia, and it is a basic concept underlying markets of all kinds.
What I meant by "there is only one type of profit" is that profit in all your definitions can also be stated as selling price minus cost price. In the context of this discussion the distinction is meaningless, because regardless of how you obtained that margin, whether by speculation or not, it does not neccessarily tend to zero in open markets!